U.S. patent application number 12/101640 was filed with the patent office on 2008-10-16 for system and method for testing and calibrating a control unit using an adaptation unit.
This patent application is currently assigned to dSpace digital signal processing and control engineering GmbH. Invention is credited to Marc-Andre Dressler, Hans-Guenther Limberg, Andre Rolfsmeier.
Application Number | 20080256268 12/101640 |
Document ID | / |
Family ID | 39829123 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080256268 |
Kind Code |
A1 |
Dressler; Marc-Andre ; et
al. |
October 16, 2008 |
SYSTEM AND METHOD FOR TESTING AND CALIBRATING A CONTROL UNIT USING
AN ADAPTATION UNIT
Abstract
A system and method for testing and calibrating a control unit
including a microcontroller includes an influencing device and an
adaptation unit. The adaptation unit includes a memory that can
store at least part of a data of a data communication between the
influencing device and the control unit. The memory can be read
from and/or written to by the microcontroller of the control unit
when the control unit is in an on state.
Inventors: |
Dressler; Marc-Andre; (Horn,
DE) ; Limberg; Hans-Guenther; (Paderborn, DE)
; Rolfsmeier; Andre; (Bad Lippspringe, DE) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Assignee: |
dSpace digital signal processing
and control engineering GmbH
Paderborn
DE
|
Family ID: |
39829123 |
Appl. No.: |
12/101640 |
Filed: |
April 11, 2008 |
Current U.S.
Class: |
710/33 |
Current CPC
Class: |
G05B 2219/25064
20130101; G05B 19/042 20130101; G05B 2219/21109 20130101; G05B
2219/2637 20130101 |
Class at
Publication: |
710/33 |
International
Class: |
G06F 13/00 20060101
G06F013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 13, 2007 |
DE |
10 2007 017 865.6 |
Claims
1. A system for testing and calibrating a control unit including a
microcontroller, the system comprising: an influencing device; and
an adaptation unit disposed between the control unit and the
influencing device, the adaptation unit including a memory operable
to store at least part of a data of a data communication between
the influencing device and the control unit, the memory operable to
be at least one of read from and written to by the microcontroller
of the control unit in an on state of the control unit.
2. The system as recited in claim 1, wherein the adaptation unit
includes a connecting element operable to connect the influencing
device and the control unit via at least one of a direct data link
and a data link interposing the memory of the adaptation unit, the
connecting element being switchable independently of the state of
the control unit.
3. The system as recited in claim 2, wherein the connecting element
includes at least one programmable unit.
4. The system as recited in claim 3, wherein the connecting element
includes a reprogrammable hardware device.
5. The system as recited in claim 2, wherein the connecting element
is implemented within an FPGA.
6. The system as recited in claim 2, further comprising a
microcontroller bus, and wherein the adaptation unit includes a
filter element connected to the microcontroller bus and operable to
supply a trigger signal to the connecting element.
7. The system as recited in claim 2, further comprising a filter
element, and wherein: the influencing device includes a debug
interface operable to supply a trigger signal; and the filter
element is operable to extract the trigger signal so as to supply
the extracted trigger signal to the connecting element.
8. The system as recited in claim 2, wherein the connecting element
includes a microcontroller device.
9. The system as recited in claim 2, wherein the connecting element
includes a circuit including discrete active and passive electronic
components.
10. The system as recited in claim 1, wherein the memory of the
adaptation unit includes at least one of a SRAM, MRAM, and FRAM
device.
11. The system as recited in claim 1, wherein: the influencing
device includes a first debug interface; the control unit includes
a second debug interface; and the adaptation unit includes a third
debug interface corresponding to the first and second debug
interfaces and being operable for a data connection to at least one
of the influencing device and to the control unit.
12. The system as recited in claim 11, wherein the third debug
interface is a NEXUS interface.
13. The system as recited in claim 1, wherein the adaptation unit
is an integral part of at least one of the influencing device and
the control unit.
14. A method for operating a test system having a control unit and
an influencing device connected to the control unit via a data link
and used for influencing the control unit, the method comprising
the steps of: providing an external memory that is accessible by
the control unit as its own memory; providing protocol data on a
debug channel; providing at least one of first control data, first
payload data, and first instructions on at least one of the data
link between the control unit and the influencing device and a data
link between an adaptation unit and the influencing device;
establishing a communication between the external memory and the
influencing device using at least one of communication protocol
data of the control unit and communication protocol data which
corresponds to communication protocol data of the control unit;
writing at least one of second control data, second payload data,
and second instructions for the control unit from the influencing
device into the external memory; starting the control unit while
reading the external memory; and transferring the communication to
the control unit and the influencing device.
15. The method as recited in claim 14, further comprising the step
of: decoupling the external memory from the influencing device
after the transferring of the communication to the control unit and
the influencing device.
16. The method as recited in claim 14, wherein the external memory
is disposed in the adaptation unit.
17. The method as recited in claim 16, wherein the communication is
a communication via a respective debug interface of at least one of
the control unit, the influencing device, and the adaptation
unit.
18. An adaptation unit connected in a data link between a control
unit and an influencing device, the adaptation unit comprising a
memory operable to store at least part of a data of a data
communication between the influencing device and the control unit,
the memory being operable to be at least one of read from and
written to by a microcontroller of the control unit when the
control unit is in an on state.
19. The adaptation unit as recited in claim 18, wherein the
adaptation unit comprises a connecting element operable to connect,
via the data link, the influencing device alternatively to the
control unit and the memory of the adaptation unit, the connecting
element being switchable independently of a state of the control
unit.
20. The system as recited in claim 1, wherein the adaptation unit
includes a connecting element operable to connect the influencing
device and the control unit via at least one of a direct data link
and a data link interposing the memory of the adaptation unit, the
connecting element being switchable based on the state of the
control unit.
Description
[0001] Priority is claimed to German Patent Application DE 10 2007
017 865.6, filed Apr. 13, 2007, the contents of which is
incorporated herein by reference as if set forth in its
entirety.
[0002] The present invention relates to a system and method for
calibrating and testing a control unit using an adaptation unit
disposed between the control unit and an influencing device.
BACKGROUND
[0003] A tendency that has been observed for many years in the
manufacture of not only automobiles, but also in other sectors in
the design and manufacture of vehicles of any type, and in all
other mechanical engineering and plant construction sectors, is
that the products contain more and more electronics. The
contribution of electronics to automotive value creation is already
about 35 percent, with an upward tendency. A large portion of this
contribution to value creation is related to control units which
monitor the various devices of the overall products. These
traditional control units are generally permanently programmed, and
cannot be modified at all, or only to a very limited extent, at a
later time.
[0004] However, in order to adapt the control units to their
respective environments, it is necessary to be able to make
modifications to the control unit in order to determine the optimum
operating parameters for a particular application. Such
modifications relate mainly to changes to boundary conditions,
i.e., to changes to the data stored in the memories of the control
unit.
[0005] In order to be able to carry out suitable tests on the
respective control units, one can use influencing devices, which
allow the desired modifications to be made to the control unit.
[0006] Influencing devices are known in the field and are used
primarily in applied research and industrial development where the
aim is to develop control units and bring them into use. An example
of an influencing device is described in International Patent
Application WO 2005/091089 A1.
[0007] In the following, the term "control unit" will be understood
to include all types of electronic devices used for influencing
technical-physical processes. Such a control unit usually includes
at least one processing unit, for example in the form of a
microprocessor or microcontroller. The control unit also includes a
memory and input/output (I/O) interfaces to be able to perform
calculations as a function of internally stored parameters or
internal operands and/or measured (or at least externally provided)
variables and, at the same time, to be able to influence external
processes by outputting electrical signals. Thus, from a control
engineering point of view, control units do not just operate as
open-loop controllers. Rather, they are, in particular, also
capable of performing complex closed-loop control tasks. Whenever
the description below refers to control units, controllers, and the
process of controlling, it is understood that these terms also
include devices and processes according to the more general
definition given above.
[0008] Moreover, the following description frequently refers to
various microcontrollers, which will be understood to mean
electronic processing units having electronic memory associated
therewith, irrespectively of whether the memory is partially or
completely implemented together with the processing unit in a
single part, or whether the processing unit and the associated
memory are separate parts.
[0009] The use of influencing devices is illustrated in the
following description of the development process that control units
go through in practice, at least with respect to complex tasks.
[0010] Any control engineering task begins with the mathematical
modeling and simulation of a technical-physical process upon which
a desired dynamic behavior is to be imposed. Based on the resulting
abstract mathematical model, it is possible to test different
control concepts, again available exclusively as a mathematical
model concept, within the framework of numerical simulations. This
stage is the phase of modeling and controller design, based mostly
on computer-aided modeling tools.
[0011] In a second step, the controller designed in the
mathematical model is transferred to a real-time capable simulation
unit, which usually has a much better performance than a
conventional standard control unit in terms of both computing power
and I/O capabilities, and which is in an interactive communication
with the real physical process. Since the transfer of the
abstractly-formulated controller from a modeling tool to the
simulation unit occurs substantially automatically, the second
phase is also referred to as rapid control prototyping (RCP) or
function prototyping.
[0012] Once the control engineering task is achieved by the
controller operating in the simulation unit, the control algorithm
is transferred, during controller implementation, to the standard
control unit to be ultimately used in practice, usually in a fully
automatic manner.
[0013] Frequently, the control unit, which in principle can now be
used in a real process, is initially subjected to a test before it
is used in practice. In such a test, the real process, with which
the control unit is ultimately intended to interact with, is
partially or completely simulated by a real-time capable simulation
unit, and the control unit is simulated by a signal test pattern
(e.g., hardware-in-the-loop simulation). The control unit tested in
this manner is ultimately used in the real process and operated
interactively therewith.
[0014] In spite of the previously performed comprehensive testing,
it is usually necessary to make adjustments to the control unit, or
to the functions implemented in the control unit. For this purpose,
first of all, the state of the control unit, i.e., all data that is
read or output or internally used by the control unit, must be
capable of being promptly monitored, recorded, and analyzed through
data acquisition. Secondly, the parameters or sets of parameters,
i.e., the characteristic values, curves, and maps, on which the
functions/control algorithms are based, must be capable of being
changed through writing access to the memory of the control unit.
The above-described processes are altogether referred to as control
unit applications.
[0015] In cases where not only parameters of the functions of the
control unit, i.e., data stored in the memory of the control unit,
but also the actual functions implemented in the control unit are
to be changed for testing purposes, the so-called "function
bypassing" is used. During function bypassing, the control unit
signals to a real-time capable simulation unit that a control unit
function has been called, but does not itself perform the function.
Instead, the control unit receives and uses the result calculated
in the simulation unit for purposes of substitution. Thus, the
control unit function is bypassed.
[0016] In both the control unit application and function bypassing
scenarios described above, it is necessary to provide a special
access to the control unit, via which the control unit can be
monitored and actively influenced. This is the task of influencing
devices.
[0017] In practice, various methods are known for accessing control
units via influencing devices. These methods include access via a
parallel interface, access via a serial interface, or access via a
special debug interface, frequently in addition to other serial
and/or parallel interfaces. The debug interface itself may be in
the form of a serial or parallel interface, or be a combination of
these two types.
[0018] Depending on the design of the control unit, it may be
necessary to interfere with the hardware of the control unit when
using a parallel interface, because frequently the influencing
device operates as a memory emulator.
[0019] It is known that a memory, or selected memory areas of the
memory, of a memory emulator may take the place of a memory device
or memory area of the control unit, or be accommodated in a slot
especially provided for this purpose on the circuit board of the
control unit. After the memory emulator is connected to the control
unit, a control unit microcontroller accesses the memory contents
of the memory emulator via the address and data buses.
[0020] Modern control units are increasingly equipped with
microcontrollers having a debug interface, such as NEXUS (IEEE-ISTO
5001: "The NEXUS 5001 Forum Standard for a Global Embedded
Processor Debug Interface", 2003).
[0021] Debug interfaces offer far-reaching possibilities for
monitoring and influencing microcontroller states and allow for
run-time monitoring and control (e.g., debugging) of the
microcontroller, making it possible, in particular, to trace the
execution of program code and the data accessed and modified in the
process. Because debug interfaces form an integral part of the
microcontroller hardware, they allow the microcontroller to be
accessed much faster than is possible when using a software-based
communications interface.
[0022] Thus, using a suitable interface instruction set, the debug
interface of a control unit makes it possible to automatically read
out and actively influence the state of a control unit
microcontroller, and, to some extent, also the states of units
associated therewith in the control unit (e.g., the state of its
external memory).
[0023] The term "control unit debug interface" as used herein will
be understood to also include interfaces which are not primarily
intended as "debug interfaces" and therefore are not explicitly
referred to as such, but which offer such monitoring and
influencing capabilities with respect to the control unit
microcontroller and the electronic units associated therewith.
[0024] International Patent Publication WO 2005/091089 A1 describes
the use of the control unit debug interface for data exchange
between the influencing device and the control unit to be
influenced.
[0025] It is also known that the application of a control unit
having a control unit debug interface can be done using an
influencing device (see, dSPACE catalog 2006, pp. 430-432,
influencing device DCI-GSII) which uses the control unit debug
interface (for example, the Nexus interface) for influencing the
control unit. Until now, the exchange of data (e.g., protocol
information, variables, constants, instructions, functions,
programs, etc.) between the control unit and the influencing device
could only be carried out via such debug interfaces when the
control unit was ON.
[0026] In traditional systems, the influencing device and control
unit are directly coupled via a debug interface. However, in an
arrangement where the influencing device and the control unit are
directly coupled via a debug interface, data exchange cannot even
start when the control unit is OFF.
[0027] One of the reasons for this is that certain protocol
information must be exchanged before payload data can be exchanged
between the debug interface of the influencing device and the debug
interface of the control unit. In the special case where a control
unit microcontroller located in the control unit can be turned off
independently of the control unit, the operational readiness of the
debug interface of the control unit is usually still linked to the
operational readiness of the control unit microcontroller.
SUMMARY
[0028] However, the work of development and test engineers would be
enormously facilitated if the memory contents associated with the
microcontroller of the control unit could be influenced via the
influencing device and via the debug interface even when the
control unit is OFF. The capability of influencing the memory
(e.g., RAM memory) associated with the control unit microcontroller
via the debug interface already before or during activation of the
control unit would be beneficial especially with respect to
calibration and testing of the control unit.
[0029] An embodiment of the present invention provides a system and
method for testing and calibrating a control unit. The control unit
includes a microcontroller and has an on/off state. In the
embodiment, an influencing device and an adaptation unit is also
provided. The adaptation unit has a memory that can store at least
part of the data of a data communication between the influencing
device and the control unit. The memory can be read from and/or
written to by the microcontroller when the control unit is in the
on state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Further features and advantages of the present invention
will become apparent from the following description of the
accompanying figures without being intended to limit the invention
in any way, in which:
[0031] FIG. 1 illustrates a schematic view of a test system
according to an embodiment of the present invention, and
[0032] FIG. 2 illustrates a schematic view of a test system
according to another embodiment of the present invention.
DETAILED DESCRIPTION
[0033] In accordance with an embodiment of the present invention,
an adaptation unit is optionally provided in the data link between
a control unit and at least one influencing device for influencing
the control unit. The adaptation unit includes at least one memory
which can store at least part of the data of the data communication
between the influencing device and the control unit, and which can
be read from and/or written to by the microcontroller of the
turned-on control unit.
[0034] Such an adaptation unit according to an embodiment of the
present invention allows the memory contents associated with the
microcontroller of the control unit to be influenced via the
influencing device when the control unit is OFF, so that the memory
(e.g., RAM memory) associated with the control unit microcontroller
can be influenced via the debug interface before or during
activation of the control unit, for example, for purposes of
calibration and testing of the control unit.
[0035] One of the reasons for this is that certain protocol
information must be exchanged before payload data can be exchanged
between the influencing device and the control unit. In an
embodiment of the present invention, the adaptation unit signals to
the influencing device that the control unit is ON, even if the
control device is not turned on, or not fully turned on. In
addition, the adaptation unit enables the influencing device to
exchange data via the system's bus just as if the control unit were
ON and without having to make changes to the usage of the bus. This
means that the protocol used for controlling the bus remains
unchanged. For this purpose, the adaptation unit according to an
embodiment of the present invention simulates portions of the bus,
or the entire bus, and the entire bus protocol, respectively. In
addition, the adaptation unit according to an embodiment of the
present invention allows relevant data to be exchanged even when
the control unit is OFF.
[0036] The adaptation unit according to an embodiment of the
present invention may further feature a connecting element for
alternatively connecting the influencing device and the control
unit via a direct data link, or with interposition of the memory in
the adaptation unit. The connecting element can be switchable
independently of the state of the control unit or of signals of the
control unit or influencing device. The connecting element may also
include at least one programmable unit, preferably in the form of a
field programmable gate array device, which is referred to as a
"FPGA" by those skilled in the art. This acronym will be used
hereinafter. Alternatively, the connecting element may also be
implemented with a reprogrammable hardware device, also preferably
in the form of an FPGA.
[0037] Finally, the connecting element may also be a
microcontroller device, or be implemented as a circuit including
discrete active and passive electronic components. The memory
provided in the adaptation unit is preferably a static RAM (SRAM)
memory, called "SRAM" hereinafter. However, alternative memory
types could also be used for the adaptation unit. These alternative
memory types are not limited to volatile memory types, but may also
be non-volatile memory types. Alternative memories include, for
example, MRAM memory or FRAM memory. The adaptation unit according
to an embodiment of the present invention is also preferably
provided with at least one debug interface for data connection to
the influencing device and to the control unit. The debug interface
preferably corresponds to the interfaces of the control unit and
the influencing device, and is also preferably a NEXUS
interface.
[0038] As discussed previously, debug interfaces offer far-reaching
possibilities for monitoring and influencing microcontroller states
and allow for run-time monitoring and control (e.g., debugging) of
the microcontroller, making it possible, in particular, to trace
the execution of program code and the data accessed and modified in
the process. Because debug interfaces form an integral part of the
microcontroller hardware, they allow the microcontroller to be
accessed much faster than is possible via a software-based
communications interface. Thus, using a suitable interface
instruction set, the debug interface of a control unit makes it
possible to automatically read out and actively influence the state
of a control unit microcontroller, and to some extent also the
states of units associated therewith in the control unit (e.g., the
state of its external memory).
[0039] Furthermore, in an embodiment of the present invention, the
adaptation unit may form an integral part of the influencing
device. Usually, adaptation elements and influencing devices are
designed to be as small as possible and separate from an operator
control unit, for example, because they are mounted within a motor
vehicle. However, it is perfectly conceivable that the inventive
adaptation unit, the influencing unit, and the operator control
unit could be integrated as one unit of hardware.
[0040] An embodiment of the present invention also provides a
method for operating a test system including at least one control
unit and at least one influencing device which is connected to the
control unit via a data link and used for influencing the control
unit. The test method includes providing an external memory that is
accessible by the control unit as its own memory and providing
protocol data on a debug channel. Control data and/or payload data
and/or instructions on the data link between the control unit and
the influencing device and/or between the adaptation unit and the
influencing device is also provided. A communication between the
external memory and the influencing device is established using
either communication protocol data of the control unit, or
communication protocol data which corresponds to that of the
control unit. Control data and/or payload data and/or instructions
for the control unit from the influencing device is written into
the external memory. The control unit can be started while reading
the external memory, and the communication can be transmitted to
the control unit and the influencing device.
[0041] In an embodiment according to the present invention, the
connection between the external memory of the adaptation unit and
the control unit via the microcontroller bus and/or the connection
between the external memory of the adaptation unit and the
influencing device is/are capable of being disconnected. Moreover,
the control unit and/or the influencing device and/or the
adaptation unit may each be provided as separate modules that can
then be mechanically and/or electrically coupled to each other via
plug-in connections.
[0042] In another embodiment according to the present invention,
the adaptation unit may remain connected to the control unit during
the entire control unit test phase, which may last several days,
while, at the same time, the control unit uses the external memory
of the adaptation unit, either permanently or temporarily.
[0043] A system according to an embodiment of the present invention
is also provided. The system includes at least one control unit
having at least one control unit microcontroller. The system also
includes at least one control unit debug interface, and an
influencing device for influencing the control unit. The
influencing device includes at least one programmable unit, at
least one data transmission interface for connecting the
influencing device to an operator control unit, and at least one
influencing device debug interface which can be used for connecting
the influencing device to the debug interface of the control
unit.
[0044] FIG. 1 illustrates a control unit 2, an influencing device
4, and an adaptation unit 6 connected to the control unit 2 and to
the influencing device 4.
[0045] As shown in FIG. 1, control unit 2 also includes a
microcontroller core 8 (microcontroller core 8 is essentially the
core of the microcontroller of control unit 2), a flash memory 10,
and a RAM memory 12.
[0046] In addition, control unit 2 preferably includes a CAN
interface 14, via which the control unit communicates with CAN bus
16, for example, in a vehicle. It is to be understood that other
interfaces, usually standard ones, to other control units may be
additionally provided, depending on the use of control unit 2.
[0047] Control unit 2 further includes a debug interface 18, via
which the control unit 2 communicates with influencing device 4
using the adaptation unit 6. Debug interface 18 is preferably a
Nexus interface.
[0048] Influencing device 4, in turn, includes an influencing
device microcontroller 20, a ROM memory 22 and a RAM memory 24.
Alternatively, a so-called "flash memory" or an EPROM or an EEPROM
may be used in place of ROM memory 22.
[0049] FIG. 1 further illustrates that influencing device 4 has an
interface 26 to an operator control unit, for example, an USB
interface to a calibration tool installed on a standard computer.
In addition, influencing device 4 also has an interface 28 to an
external real-time computer, such as an LVDS interface to a bypass
system.
[0050] Influencing device 4 also has a debug interface 30, which is
also preferably a Nexus debug interface. Alternatively, other debug
interfaces, which those skilled in the automotive art refer to by
the acronyms AUD, JTAG, NBD, OCDS or SDI, etc., may be used in
place of the Nexus interface.
[0051] FIG. 1 also illustrates the adaptation unit 6, via which
influencing device 4 is connected to control unit 2. As can be seen
in FIG. 1, adaptation unit 6 includes SRAM 32, which is connected
to a FPGA 34.
[0052] The FPGA is connected to a connecting element 38 via a
channel section 36A, on which preferably simulated bus signals can
be provided, preferably by the FPGA. Connecting element 38, which
in a preferred embodiment is implemented within the FPGA, has the
switching states S1 and S2 shown in FIG. 1. Switching from a first
switching state S1 to a second switching state S2 can be triggered
by a trigger signal 40 coming from an access point to
microcontroller bus 42 of the control unit microcontroller 8. The
trigger signal 40 is preferably extractable from the data stream on
the microcontroller bus using a filter element 52 and/or said
trigger signal 40 is dependent on the switching state of the
control unit microcontroller 8 or of control unit 2 as a whole. The
present system, as shown in FIG. 1, enables control unit variables
to be calibrated, applied, and read out via debug interface 30 even
when control unit 2 is OFF.
[0053] Since adaptation unit 6 is interposed between influencing
device 4 and the control unit, adaptation unit 6 can indicate an
intact Nexus interface to influencing device 4 when control unit 2
is OFF. During switching state S2, the required bus signals are
provided by FPGA 34 of the adaptation unit 6, so that the SRAM 32
of the adaptation unit 6 is, or can be, written to via debug
interface 30 even when control unit 2 is OFF. Once control unit 2
is turned on, it can access the memory area of SRAM 32 via
microcontroller bus 42.
[0054] During "normal operation", i.e., when control unit 2 is
energized, connecting element 38 switches adaptation unit 6 to
first switching state S1, thereby reestablishing the direct link
between the control unit and influencing device 4 via Nexus debug
interfaces 18, 30.
[0055] SRAM 32 can hold the data permanently even when the control
unit is OFF. When the control unit is ON, this memory is accessed
via microcontroller bus 42 of control unit 2. When control unit 2
is ON, the control unit microcontroller core 8 communicates, inter
alia, with debug interface 18 of control unit 2. The data
communication taking place via channel sections 36B, 36C between
debug interface 18 of control unit 2 and debug interface 30 of
influencing device 4 is not influenced by adaptation unit 6 when
the control unit is in an ON state, because in this condition the
debug data, i.e., the data exchanged between debug interfaces 18,
30, is merely passed through by adaptation unit 6.
[0056] When the control unit is OFF, adaptation unit 6 takes over
the task of providing the protocol information for the debug
channel, which here includes channel sections 36A and 36C. The
adaptation unit 6 also permits influencing device 4 to continue to
access the data just as if the system were ON. Because of this,
data can be prepared while control unit 2 is OFF, and used
immediately after control unit 2 is turned on, such as is necessary
for cold start applications. If control unit 2 uses SRAM 32 of
adaptation unit 6 also for other status data, influencing device 4
can also read out these other status values for purposes of
analysis after the control unit 2 is turned off at a later
time.
[0057] These status values could, for example, be currently
recorded sensor data reflecting the state of the system, which is
controlled by the control unit, such as engine, brakes, chassis and
suspension system, etc. Intermediate results of calculations of the
control unit can also be stored in SRAM 32 as status values.
[0058] It is also conceivable that other influencing devices, such
as a debugger device (e.g., a Lauterbach debugger), could be used
in place of the influencing device 4 illustrated in FIG. 1.
Depending on the level of implementation of the "simulated" control
unit bus, it is possible to provide a greater or smaller number of
functions of other influencing devices or, with little
modifications, of influencing device 4.
[0059] The following is a detailed description of FIG. 2, which
schematically illustrates another embodiment of an adaptation unit
6 according to the present invention. Drawing elements that are not
described again in FIG. 2 are equivalent to those having the same
reference numerals and shown in FIG. 1.
[0060] In the adaptation unit 6 according to FIG. 2, a trigger
signal 40 for switching the connecting element 38 can be provided
by FPGA 34. FIG. 2 illustrates additional or alternative sources of
a trigger signal 40.
EXAMPLE A
[0061] Channel section 506, which runs from debug interface 18 of
control unit 2 to connecting element 38 of adaptation unit 6, is
connected to a filter element 51 in such a manner that a trigger
signal 40 can be extracted from the data stream on channel section
506.
EXAMPLE B
[0062] Among other things, debug interface 30 of influencing device
4 also provides a trigger signal 40, which can be extracted by a
filter element 53.
EXAMPLE C
[0063] A trigger signal 40 can be extracted from microcontroller
bus 42. The extraction of this signal from the data stream on
microcontroller bus 42 is preferably accomplished using a filter
element 52.
[0064] In the examples A through C, trigger signal 40 ultimately
causes the switching of the switching states of connecting element
38.
[0065] The data channel between influencing device 4 and adaptation
unit 6 is symbolically divided, on the one hand, into channel
sections 501, 502, and 503 with a data flow direction away from
influencing device 4 and, on the other hand, into a fourth channel
section 504 with a data flow direction toward influencing device 4.
However, this does not mean that different lines must be used for
the two data flow directions, respectively.
[0066] Preferably, connecting element 38 is implemented within FPGA
34, and influencing device 4 and adaptation unit 6 are directly
connected to FPGA 34 via the bus line system. It is also preferred
to use the same bus line system for both the data flow direction
from influencing device 4 and the data flow direction toward
influencing device 4.
[0067] FIG. 2 illustrates a first switching element 701 and second
switching element 702, which represent the two main components of
connecting element 38, and illustrate the manner in which the
different data flow directions interact with the respective
switching states of switching element 701 and second switching
element 702. In both switching elements 701 and 702, a trigger
signal 40 causes a change in the data flow, which is illustrated by
the following example.
[0068] Initially, the control unit is assumed to be in a
non-operational state. Because of this, a trigger signal 40 causes
the two switching elements 701 and 702 of connecting element 38 to
go to switching state S2. As a result of this switching state, data
which is to be transmitted from influencing device 4 to adaptation
unit 6 no longer reaches control unit debug interface 18 via second
channel section 502 and first switching element 701. It is noted
that even if the data could reach the control unit debug interface,
it would not be useful anyway, since the control unit is in a
non-operational state.
[0069] However, in this embodiment, the data of the influencing
device is transmitted to FPGA 34 via first channel section 501 and
third channel section 503, and protocol data is "replied" by the
FPGA to influencing device 4 via fifth channel section 505 and
fourth channel section 504. Thus, the communication appears to
influencing device 4 as if a connection existed to control unit
2.
[0070] When the control unit of the embodiment of FIG. 2 changes to
an operational state, then trigger signal 40 causes the two
switching elements 701 and 702 of connecting element 38 to go to
first switching state S1. This allows data to be transmitted from
influencing device 4 to control unit 2 via channel sections 501,
502 and 506. Data transmission in the opposite direction (e.g.,
from control unit 2 to influencing device 4) can take place via
sixth channel section 506 and fourth channel section 504.
[0071] Although in first switching state S1, FPGA 34 is not
required to send protocol data to the influencing device because
control unit 2 itself provides this data when in an operational
state, and adaptation unit 6 is primarily intended to merely pass
through the data traffic between influencing device 4 and control
unit 2, the inventive embodiment of FIG. 2 may provide for the data
channel originating from influencing device 4 to branch at a
junction point 601. In first switching state S1, the branch at
junction point 601 causes the data coming from debug interface 30
of influencing device 4 to be forwarded both to debug interface 18
of control unit 2 and to FPGA 34.
[0072] FPGA 34 may be designed such that the switching states of
first switching element 701 and/or of second switching element 702
are changed as a function of the transmitted data. For example, in
first switching state S1, the data is also transmitted to FPGA 34
via first channel section 501 and third channel section 503.
[0073] The dashed line leading from FPGA 34 to a first node 401 and
further to connecting element 38 illustrates that a change of a
switching state from S1 (i.e., first switching state) to S2 (i.e.,
second switching state) or vice versa can also be triggered by a
trigger signal 40 coming from FPGA 34. This can be an alternative
or supplement to providing a trigger signal 40 via microcontroller
bus 42.
[0074] Reference is also made to additional dashed lines that
indicate optional starting points of trigger signals 40 for
connecting element 38. As already mentioned, such a signal 40 may
originate from debug interface 30 of influencing device 4, and then
pass to second node 402, and from there, to connecting element 38.
The corresponding dashed line illustrates that, as an alternative,
or in addition to, the above-mentioned sources of a trigger signal
40, such a signal may originate from influencing device 4, and more
specifically, but not exclusively, from the debug interface 30
thereof.
[0075] A switching signal 40 may also be conveyed to a third node
403 from sixth channel section 506 of the bus that connects debug
interface 18 of control unit 2 to connecting element 38 of
adaptation unit 6, or from debug interface 18 itself. The signal 40
is preferably extractable from the data stream on channel section
506 using the filter element 51. Switching signal 40 passes from
third node 403 to connecting element 38, as shown in FIG. 2 by the
dashed line leading from third node 403 via second node 402 to
connecting element 38.
[0076] In an embodiment of the present invention, a separate
digital output of control unit 2 can be provided as a possibly
additional source of a switching signal 40. Preferably, switching
signal 40 is conveyed from the digital output to one of nodes 401,
402, or 403, and from there, passes to connecting element 38.
[0077] While the invention has been described in connection with
certain embodiments thereof, the invention is capable of being
practiced in other forms and using other materials and structures.
Accordingly, the invention is defined without limitation by the
recitations in the claims appended hereto and equivalents
thereof.
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